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Subject: Re: Question about Tegra UCMs
To:     Jaroslav Kysela <perex@perex.cz>, Mark Brown <broonie@kernel.org>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Takashi Iwai <tiwai@suse.com>, Ion Agorria <ion@agorria.com>,
        Svyatoslav Ryhel <clamor95@gmail.com>,
        Frank Rowand <frowand.list@gmail.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        linux-tegra@vger.kernel.org, devicetree@vger.kernel.org,
        alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org,
        Rob Herring <robh@kernel.org>
References: <20210518001356.19227-1-digetx@gmail.com>
 <20210518001356.19227-3-digetx@gmail.com>
 <20210518180949.GA949047@robh.at.kernel.org>
 <20210518183455.GE4358@sirena.org.uk>
 <92cef674-c454-e08c-b44d-d8c08b1e8ccf@gmail.com>
 <562efe35-dd91-12a0-96a5-b8f4f34ea153@perex.cz>
From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <d5944fc0-4f8a-9881-c336-b418d76540c5@gmail.com>
Date:   Wed, 19 May 2021 16:15:43 +0300
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19.05.2021 14:13, Jaroslav Kysela пишет:
> Dne 19. 05. 21 v 0:31 Dmitry Osipenko napsal(a):
>> Mark, could you please help me to understand the UCM naming scheme that ALSA uses..
>>
>> About a year ago I tried to complain to Jaroslav Kysela in a comment to the UCM change [1] that it should be breaking the naming scheme of Tegra UCMs, but haven't got a meaningful reply and moved on to other things.
>>
>> [1] https://github.com/alsa-project/alsa-ucm-conf/commit/8ff2d50745efbb6959324f672460e413f0b618b8
> 
> I'm sorry about that, but it's better to create a tracked ticket (issue or
> pull request).
> 
>> Today I noticed that the naming scheme changed again and I still don't understand what to do about it.
>>
>> I have two devices:
>>
>>  1. Acer Picasso tablet that uses "Acer Iconia Tab A500 WM8903" for the card model name.
>>
>>  2. Google Nexus 7 that uses "ASUS Google Nexus 7 ALC5642".
>>
>> Previously UCMs were picked up by pulseaudio from these paths:
>>
>>  1. /usr/share/alsa/ucm2/Acer Iconia Tab A500 WM8903/
>>  2. /usr/share/alsa/ucm2/ASUS Google Nexus 7 ALC5642/
>>
>> Now the lookup paths are changed to:
>>
>>  1. /usr/share/alsa/ucm2/Acer_Iconia_Tab/
>>  2. /usr/share/alsa/ucm2/ASUS_Google_Nex/
> 
> Yes, it's based on the driver name (which is incorrectly set /or not set/ in
> your case).
> 
> Lookup paths (with description):
> 
> https://github.com/alsa-project/alsa-ucm-conf/blob/master/ucm2/ucm.conf
> 
> The latest scheme is even different - lookups were moved to ucm2/conf.d with
> redirection to the more descriptive layered configuration tree structure, so
> the other developers can immediately identify the hardware which is
> configured. See Qualcomm examples. The long card names does not help us so much.
> 
>> Strace shows that pulseaudio searches UCMs only at these paths.
>>
>> The output of /proc/asound/cards:
>>
>>  0 [WM8903         ]: Acer_Iconia_Tab - Acer Iconia Tab A500 WM8903
>>                       Acer Iconia Tab A500 WM8903
>>
>>  0 [ALC5642        ]: ASUS_Google_Nex - ASUS Google Nexus 7 ALC5642
>>                       ASUS Google Nexus 7 ALC5642
> 
> Fields are explained in:
> 
> https://github.com/alsa-project/alsa-ucm-conf/blob/master/ucm2/README.md
> 
>> Is there anything on the kernel side that I could change to get a working naming scheme? If yes, I may try to do something about it in the v2, thanks in advance.
> 
> Try to set a meaningful driver name (usually the code handling the ASoC card
> creation). It should be very close to the kernel module name (but more user
> friendly). The current code for your hardware use the auto-generated driver
> name from the ALSA long name.

The current name isn't auto-generated, it's specified via the
nvidia,model device-tree property.

> Then try to reuse the existing configs - for example your Nexus 7 config has
> many blocks from codecs/rt5640/* .
> 
> Anyway, create a PR so we can discuss the details.

I will create the PR, thank you very much. It's important problem which
can't be postponed anymore since sound doesn't work without UCMs on
Tegra devices.